A CDN (Content Delivery Network) is a network of servers that stores and distributes content to clients. These servers are typically located in data centres, and they can be used to improve performance by reducing latency, ensuring that the content is available at the right time, and ensuring that the content is delivered in a timely manner.

CDNs are most commonly used to store static content, such as images and videos, but they can also be used to store dynamic content, such as HTML or JavaScript. CDNs can also be used to deliver content from one location to another, such as from a website to a mobile device.

CDNs are an important part of the Internet infrastructure because they allow content to be stored and distributed in a more efficient way. They also allow content to be served from multiple locations, which can improve performance and reduce latency.

There are numerous applications for CDN, including :

* By giving static content a central location.
* By giving dynamic content a central location.
* Giving content from several sources a central spot.
* Giving material from several data centers a central location.
* Giving essential infrastructure elements, such servers and routers, redundancy.

Due to their role in ensuring that the Internet functions properly for everyone, CDNs are a crucial component of the Internet infrastructure. They aid in ensuring that everyone has simultaneous access to the same information.